Solution State-Like Reactivity of a Flexible Crystalline Werner-Type Metal Complex.

Flexible crystalline solids exhibit unique properties in response to external stimuli like heat and light. However, challenges exist in developing crystalline solids that have similar degrees of flexibility as in solution. Herein, we report the preparation of the new flexible crystalline metal complex [Cd(CF 3 SO 3 ) 2 (4-spy) 4 ] (4-spy=4-styrylpyridine), which contains photoreactive 4-spy ligand. Unlike traditional solids, this metal complex displays solution state-like [2+2] photocycloaddition reactivity. Specifically, UV irradiation of the crystalline material leads to formation of the same diverse array of dimers and cis isomer that are generated by photoreaction in the solution state. In addition, the photoresponsive flexibility of the solid leads to a photosalient effect and photo-induced formation of pores. The origin of the solution state-like photoreactivity of the solid is related to properties of the Cd(II) cation and fluorinated CF 3 SO 3 anion, and the multi-orientational arrangement of the 4-spy ligands.